The present invention relates to a magnetic disk drive accommodating a magnetic disk for storing data and, more particularly, to the structure of a spindle motor incorporated in a magnetic disk drive for rotating a stack of disks mounted thereon.
It is a common practice with computers and word processors to install a magnetic disk drive for driving a magnetic data recording medium or media, e.g., floppy disks, hard disks or similar magnetic disks. The magnetic disk drive usually rotates magnetic disks by a spindle motor. Hard disks, for example, are mounted on the spindle motor to be rotatable integrally therewith. Today, the rotation speed of the spindle motor is increasing to implement a high speed magnetic disk drive. In this respect, the conventional spindle motor of the type carrying disks integrally therewith as mentioned above has a problem, as follows. This type of spindle motor has an armature or coil affixed to a shaft. When a great current is fed to the armature to increase the rotation speed of the spindle motor, the armature oscillates. The oscillation is transmitted to a housing and a cover via the shaft, causing them to oscillate and produce noise.